Tag: bacteriological media

The approach to teaching Microbiology labs at McMurry is really an exercise in making something from nothing. This next week my BIOL 3410 students will be conducting growth curves of bacteria. That is nothing unusual for students in a course like this. However, my McMurry students have been challenged with creating their own broth media from scratch using kitchen items. The competition pits groups against one another to come up with a medium that will support the growth of microbes. We prepared on broths on Thursday, first step being to make sure their clear broths will survive autoclaving. It is always fun to see what they come up with – this semester one group found the fluid from a can of tuna fish doesn’t make a clear broth as well as an extract from boiled spinach and potato. SlimFast didn’t work so well, creating an opaque medium unsuitable for our study. Another group found a protein supplement and vitamin water made a very nice medium. Tuesday and Wednesday the games begin!

The organisms they will use are another exercise in making something from nothing, as they are the natural isolates (Staphylococci and enteric organisms) my students collected, purified, and identified earlier in the course. Each group will try their medium with six of the cocci and six enterics, following growth spectrophotometrically. Then the results will be pooled to see whose medium maximized the growth for the greatest number of bacteria. All groups will report their results in the form of research posters that will adorn our walls for the remainder of the semester. Winner gets an automatic advantage on their poster grade.

I could have given each group an organism and made their medium for them. But what would my students have learned about the chemistry and content of media by doing that? What would they have learned about the distribution of microbes in nature and the thought that goes into identifying them if I had given them cultures from our stock collection? If you can get as much “bang for your buck” making something from nothing, why not make learning fun and relevant?

There is a way of teaching that brings deeper learning, the fun of competition, and the satisfaction of accomplishment in demonstrating mastery of skills and knowledge through problem-solving. It is called discovery-based learning. We do that through research-rich teaching. McMurry’s BIMS program is committed to doing more to bring the science out of students – just putting science into students is not enough!